sergiotarxz
/
libvips
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Fix flatten clip (#2432) 

* fic gtk-doc typenames in cgif

* fix flatten clipping

flatten could produce out of range values if max_alpha was less than
the limit of the numeric range of the format

https://github.com/libvips/libvips/issues/2431
This commit is contained in:
John Cupitt 2021-09-13 11:23:02 +01:00 committed by GitHub
parent 5ab66e16e1
commit 7e8af07c66
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
6 changed files with 117 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
ChangeLog
View File

@ -6,6 +6,8 @@
- add gifsave [lovell]
- arrayjoin minimises inputs during sequential processing, saving a lot of
memory and file descriptors
- add vips_image_get_format_max()
- flatten handles out of range alpha and max_alpha correctly
16/8/21 started 8.11.4
- fix off-by-one error in new rank fast path

65
libvips/conversion/flatten.c
View File

@ -9,6 +9,8 @@
* - add max_alpha to match vips_premultiply() etc.
* 25/5/16
* - max_alpha defaults to 65535 for RGB16/GREY16
* 12/9/21
* - out of range alpha and max_alpha correctly
*/
/*
@ -177,7 +179,7 @@ vips_flatten_black_gen( VipsRegion *or, void *vseq, void *a, void *b,
VipsPel *in = VIPS_REGION_ADDR( ir, r->left, r->top + y );
VipsPel *out = VIPS_REGION_ADDR( or, r->left, r->top + y );
switch( flatten->in->BandFmt ) {
switch( ir->im->BandFmt ) {
case VIPS_FORMAT_UCHAR:
VIPS_FLATTEN_BLACK_INT( unsigned char );
break;
@ -242,7 +244,7 @@ vips_flatten_gen( VipsRegion *or, void *vseq, void *a, void *b,
VipsPel *in = VIPS_REGION_ADDR( ir, r->left, r->top + y );
VipsPel *out = VIPS_REGION_ADDR( or, r->left, r->top + y );
switch( flatten->in->BandFmt ) {
switch( ir->im->BandFmt ) {
case VIPS_FORMAT_UCHAR:
VIPS_FLATTEN_INT( unsigned char );
break;
@ -285,18 +287,18 @@ vips_flatten_gen( VipsRegion *or, void *vseq, void *a, void *b,
return( 0 );
}
static int
vips_flatten_build( VipsObject *object )
{
VipsObjectClass *class = VIPS_OBJECT_GET_CLASS( object );
VipsConversion *conversion = VIPS_CONVERSION( object );
VipsFlatten *flatten = (VipsFlatten *) object;
VipsImage **t = (VipsImage **) vips_object_local_array( object, 1 );
VipsImage **t = (VipsImage **) vips_object_local_array( object, 4 );
VipsImage *in;
int i;
gboolean black;
VipsBandFormat original_format;
if( VIPS_OBJECT_CLASS( vips_flatten_parent_class )->build( object ) )
return( -1 );
@ -315,12 +317,6 @@ vips_flatten_build( VipsObject *object )
if( vips_check_noncomplex( class->nickname, in ) )
return( -1 );
if( vips_image_pipelinev( conversion->out,
VIPS_DEMAND_STYLE_THINSTRIP, in, NULL ) )
return( -1 );
conversion->out->Bands -= 1;
/* Is max-alpha unset? Default to the correct value for this
* interpretation.
*/
@ -329,37 +325,72 @@ vips_flatten_build( VipsObject *object )
in->Type == VIPS_INTERPRETATION_RGB16 )
flatten->max_alpha = 65535;
/* Is max_alpha less than the numeric range of this image? If it is,
* we can get int overflow.
*
* This is not a common case, so efficiency is not so important.
* Cast to double, then cast back to the input type right at the end.
*/
original_format = VIPS_FORMAT_NOTSET;
if( vips_band_format_isint( in->BandFmt ) &&
flatten->max_alpha <
vips_image_get_format_max( in->BandFmt ) ) {
original_format = in->BandFmt;
if( vips_cast( in, &t[1], VIPS_FORMAT_DOUBLE, NULL ) )
return( -1 );
in = t[1];
}
t[2] = vips_image_new();
if( vips_image_pipelinev( t[2],
VIPS_DEMAND_STYLE_THINSTRIP, in, NULL ) )
return( -1 );
t[2]->Bands -= 1;
/* Is the background black? We have a special path for this.
*/
black = TRUE;
for( i = 0; i < VIPS_AREA( flatten->background )->n; i++ )
if( vips_array_double_get( flatten->background, NULL )[i] !=
0.0 ) {
for( i = 0; i < VIPS_AREA( flatten->background )->n; i++ ) {
const double *background =
vips_array_double_get( flatten->background, NULL );
if( background[i] != 0.0 ) {
black = FALSE;
break;
}
}
if( black ) {
if( vips_image_generate( conversion->out,
if( vips_image_generate( t[2],
vips_start_one, vips_flatten_black_gen, vips_stop_one,
in, flatten ) )
return( -1 );
in = t[2];
}
else {
/* Convert the background to the image's format.
*/
if( !(flatten->ink = vips__vector_to_ink( class->nickname,
conversion->out,
if( !(flatten->ink = vips__vector_to_ink( class->nickname, t[2],
VIPS_AREA( flatten->background )->data, NULL,
VIPS_AREA( flatten->background )->n )) )
return( -1 );
if( vips_image_generate( conversion->out,
if( vips_image_generate( t[2],
vips_start_one, vips_flatten_gen, vips_stop_one,
in, flatten ) )
return( -1 );
in = t[2];
}
if( original_format != VIPS_FORMAT_NOTSET ) {
if( vips_cast( in, &t[3], original_format, NULL ) )
return( -1 );
in = t[3];
}
if( vips_image_write( in, conversion->out ) )
return( -1 );
return( 0 );
}

18
libvips/foreign/cgifsave.c
View File

@ -418,9 +418,9 @@ vips_foreign_save_cgif_buffer_init( VipsForeignSaveCgifBuffer *buffer )
*
* Optional arguments:
*
* * @dither: %double, quantisation dithering level
* * @effort: %int, quantisation CPU effort
* * @bitdepth: %int, number of bits per pixel
* * @dither: %gdouble, quantisation dithering level
* * @effort: %gint, quantisation CPU effort
* * @bitdepth: %gint, number of bits per pixel
*
* Write a VIPS image to a file as GIF.
*
@ -459,9 +459,9 @@ vips_gifsave( VipsImage *in, const char *filename, ... )
*
* Optional arguments:
*
* * @dither: %double, quantisation dithering level
* * @effort: %int, quantisation CPU effort
* * @bitdepth: %int, number of bits per pixel
* * @dither: %gdouble, quantisation dithering level
* * @effort: %gint, quantisation CPU effort
* * @bitdepth: %gint, number of bits per pixel
*
* As vips_gifsave(), but save to a memory buffer.
*
@ -509,9 +509,9 @@ vips_gifsave_buffer( VipsImage *in, void **buf, size_t *len, ... )
*
* Optional arguments:
*
* * @dither: %double, quantisation dithering level
* * @effort: %int, quantisation CPU effort
* * @bitdepth: %int, number of bits per pixel
* * @dither: %gdouble, quantisation dithering level
* * @effort: %gint, quantisation CPU effort
* * @bitdepth: %gint, number of bits per pixel
*
* As vips_gifsave(), but save to a target.
*

1
libvips/include/vips/header.h
View File

@ -164,6 +164,7 @@ int vips_image_get_width( const VipsImage *image );
int vips_image_get_height( const VipsImage *image );
int vips_image_get_bands( const VipsImage *image );
VipsBandFormat vips_image_get_format( const VipsImage *image );
double vips_image_get_format_max( VipsBandFormat format );
VipsBandFormat vips_image_guess_format( const VipsImage *image );
VipsCoding vips_image_get_coding( const VipsImage *image );
VipsInterpretation vips_image_get_interpretation( const VipsImage *image );

41
libvips/iofuncs/header.c
View File

@ -414,6 +414,47 @@ vips_image_get_format( const VipsImage *image )
return( image->BandFmt );
}
/**
* vips_image_get_format_max: (method)
* @image: image to get from
*
* Returns: the maximum numeric value possible for this format.
*/
double
vips_image_get_format_max( VipsBandFormat format )
{
switch( format ) {
case VIPS_FORMAT_UCHAR:
return( UCHAR_MAX );
case VIPS_FORMAT_CHAR:
return( SCHAR_MAX );
case VIPS_FORMAT_USHORT:
return( USHRT_MAX );
case VIPS_FORMAT_SHORT:
return( SHRT_MAX );
case VIPS_FORMAT_UINT:
return( UINT_MAX );
case VIPS_FORMAT_INT:
return( INT_MAX );
case VIPS_FORMAT_FLOAT:
case VIPS_FORMAT_COMPLEX:
return( FLT_MAX );
case VIPS_FORMAT_DOUBLE:
case VIPS_FORMAT_DPCOMPLEX:
return( DBL_MAX );
default:
return( -1 );
}
}
/**
* vips_image_guess_format: (method)
* @image: image to guess for

17
test/test-suite/test_conversion.py
View File

@ -8,7 +8,7 @@ import tempfile
import shutil
import pyvips
from helpers import IMAGES, JPEG_FILE, unsigned_formats, \
from helpers import IMAGES, JPEG_FILE, RGBA_FILE, unsigned_formats, \
signed_formats, float_formats, int_formats, \
noncomplex_formats, all_formats, max_value, \
sizeof_format, rot45_angles, rot45_angle_bonds, \
@ -378,6 +378,21 @@ class TestConversion:
for x, y in zip(pixel, predict):
assert abs(x - y) < 2
# if the image has max_alpha less than the numeric range of the
# format, we can get out of range values ... check they are clipped
# correctly
rgba = pyvips.Image.new_from_file(RGBA_FILE)
im = rgba * 256
im = im.cast("ushort")
im = im.flatten()
im2 = rgba * 256
im2 = im2.flatten()
im2 = im2.cast("ushort")
assert(abs(im - im2).max() == 0)
def test_premultiply(self):
for fmt in unsigned_formats + [pyvips.BandFormat.SHORT,
pyvips.BandFormat.INT] + float_formats: